Method for producing foam for fire extinguishing purposes



c. WAGENER LZLQM,

METHOD FOR PRODUCING FOAM FOR FIRE EXTINGUISHING PURPOSES Sept 1, 1931.

Filed April 24, 1926 INVENTOR Cum/vs WAGf/VER ATTORNEY Patented Sept. 1 1931 UNITED- STATES- cLmNs WAGENER,

PATENT OFFICE or BERLIN, GERMA/NY, .ASSIGNOR "r PYRRNE-MINI Ax 00R- PORATION, A CORPORATION or DELAWARE METHOD FOR PRODUCING roam roR FI E EXITINGUISHING PURPOSES Applicationfiled April 24, 1926, Serial No. 104,368, and in Germany June.8, 1923.

* My invention relates to am'ethod of producing foam for fire extinguishing purposes.

My improved method consists in intimately mixing, by mechanical means, steam, gas

5 .or a gas mixture, such as air, with a liquid containing a foam-forming agent. This method may, for example, be carried out by allowing the liquid containing the foam generator to issue, in the form of a fine jet under pressure, from a nozzle and causing it to suck in the gas or the like to be admixed with the liquid, by the suction action of this jet. Or if desired steam, gas or a gas mixture, such as compressed air, maybe allowed to issue through a nozzle and the jet of'the gaseousmedinm caused to suck in the liquid containing the foam generator. This may be accomplished, for example, by a waterjet air-pump, an injector or the like.

Instead of directly forcing the solution of the foam generating substance, for example a saponin solution, through the wateret air- .pump, a foam generating agent may equally well be admixed'witli simply a jet of water passed through the pump, the agent being sucked up by the action of the pump itself or being forced into it from the outside.

According to another modification, making use of an injector or ejector, the apparatus may be arranged and employed to suck the liquid containing the foam generator from a tank. This tank may be open at the top so that its contents may be replenished as required during the progress of the extinguishing work. in case the normal initial contents of the tank should not suflice to extinguish the fire to be dealt with.

Another modification of the method consists in bringing together in a mixing chamher, for example that of an injector, the liquid containing the foam generator and the gas or the like. both under pressure.

It will be understood that to the solution of the foam generating substance, suitable substances or agents may be added which increase the durability of the solution and the viscosity of the foam and have a particularly favorableinfluence upon the conductivity of .ever,

ltself across a considerable distance, inasmuch as it will generally be. possible to apply the foam within the pipes. Alkaline admi-x-' tures are of particular importance in this respect.

The action of the air-pump, the injector or v the llke, may, if necessary, be assisted or in- "creased by placing in front of their outlets should be connected with the outlet of the mixing-apparatus. Frequently it will, howe unnecessary to conduct the foam the foam directly from the mixing device to the seat of the fire. Suitable apparatus for carrying out th improved method is illustrated diagrammatically in the drawings afiixed hereto.

In the drawings: i v

Fig. l is a diagram of an apparatus comprising a cylindrical container for the foam generator in the form of a powder;

Fig. 2 illustrates an apparatus in which the water-j et air-pump is directly connected with the water mains, and

Fig. 3 illustrates a slight modification of the apparatus illustrated in Fig. 2.

Like letters of. reference denote similar parts throughout all the figures of the drawmgs.

Referring to Fig. 1 of the drawings, h designates, for example, a cylindrical receptaole which contains the foam generator in the form'of a powder and which in known manner is so designed that in it the chemicals are dissolved by a stream of water passing through it. This receptacle is connected with the water mains by a pipe 71 and with the jet air-pump d by means of a pipe k. Air or other gaseous medium may be sucked in through a pipe e due to the action of the j et air-pump or may be forced in under pressure .by connecting the pipe 0 to any suitable source of the medium under pressure. WVith the outlet branch f, discharging the. foamfrom the pump, there is connected',-by;means ofa tube for conveying the foam ,to the fire. The pump could, however, equally well convey the foam directly to the seat of the fire.

Referring to Fig. 2 ofthe drawings, it will be seen that the jet pump d is directly connected with the water mains by a pipe Z. Upon the pump is mounted a receptable m which contains a foam generator, for example saponin, in the form of a powder or a concentrated solution. If desired a cock may be interposed between the receptacle and the pump. As soon as the pump is started the contents ofthe receptacle m is allowed to flow into the suction jet of thepump, if necessary under pressure which may also be derived from the water mains, through a pipe n the water acting under pressure on a piston or disc above the agent in m so that the jet absorbs the foam generating agent and produces the foam generating solution -to be dealt with by the pump. The apparatus shown in this figure might, in lieu of the arrangement mentioned, have the pipe-Z connected to a source of compressed air or steam or the like and have the pipe 6 connected to a source of water so that the water-would be drawn in by. the suction action of the gaseous medium.

The embodiment illustrated in Fig. 3 of the drawings differ from that represented in Fig. 2 in that the foam generator in the form of a powder or in solution is conveyed to the suction jet in the stream'of the sucked in airor by this stream. For this purpose the receptacle m is made to discharge directly into the air suction pipe 6.

In any of the. forms of apparatus shown suitable chemical substances may be added to the solution of the foam generator or to the powder used, according-to the purpose contemplated. In the event of an open receptacle or tank 772. being employed in conjunction with the embodiments illustrated in Figs. 2 and 3, as indicated in Figure 3 continuous operation is rendered possible without the addition of any further apparatus. In the embodiments according to Figure 1, continuous operation may be provided for, in well known manner, by disposing between the water mains and the jet air-pump two of the receptacles a or h, respectively, connected in parallel as indicated by the dotted line showing of a receptacle k in Figure'l.

In any of the embodiments illustrated the effect of the jet air-pump may, if necessary or desired, be supplemented or increased by placing in front of its outlet a distributing or baffling device, such as indicated at p in Figure 2, which serves to reduce excessively large foam bubbles.

While I have shown my invention in the preferred form, it is obvious that various modifications and changes may be made without departing from the spirit and scope of the invention, and I desire, therefore, that only such limitations shall be placed thereon as are imposed by the prior art.

Where the terms free gas and free gaseous medium are employed in theclaims, they are to be understood to refer to a medium existing in a gaseous state prior to thedevelopment of the foam as distinguished from a gas developed by chemical reaction in the course of producing the foam.

l Vhat I claim is:

1. The method of producing a fire extinguishing foam which comprises-introducing into a flowing stream of water a saponaceous substance by the suction action of said stream, simultaneously introducing into said stream by the suction action a free gas in such a manner as to physically act upon said saponaceous substance to produce foam, and s taneously adding to said stream an agent to render said foam durable.

2. The method of producing a fire extinguishing foam which comprises introducing into a flowing stream of water a saponaceous substance by the suction action of the stream,

and simultaneously introducing into said stream, by the suction action thereof, air in such manner as to physically act upon said saponaceous substance to produce foam.

3. The method of producing a fire extinguishing foam which comprises introducing into a flowing stream of water a saponaceous substance by the suction action of said stream, simultaneously introducing into said stream by the suction action a free gas in such a manner as to physically act upon said saponaceous substance to produce foam, and simuL taneously adding to said stream an agent to render said foam more viscous.

In testimony whereof I affix my sign ature.

CLEMENS WAGENER. 

